Plating apparatus



May 19, 1959 D. J. BORODIN PLATING APPARATUS Filed Nov. 5, 1956 5Sheets-Sheet 1 INVENTOR.

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PLATING APPARATUS Filed Nov. 5, 1956 I 5 SheeAs-Sheet 2 NA ii May 19,1959 D. J. BORODIN PLATING APPARATUS 5 Sheets-Sheet 3 Filed NOV. 5, 1956INVENTOR.

Dfi/Y/il ,d. BOROO/A BY ATTO/FA/[VJ May 19, 1 D. J. BORODIN PLATINGAPPARATUS 5 Sheets-Sheet 4 Filed Nov. 5, 1956 INVENTOR.

Ofl/V/[Z d. EOROU/A M F M May 19, 1959 D. J. BORODIN PLATING APPARATUS-5 Sheets-Sheet 5 INVENTOR.

J. eciwoo/w' 1 Filed Nov. 5, 1956 United States Patent PLATIN GAPPARATUS Daniel Borodin, Detroit, Mich., assignor, by mesneassignments, to Allied Research Products, Incorporated, Baltimore, Md.,a corporation of Maryland Application November 5, 1956, Serial No.620,505 12 Claims. (Cl. 198-19) The present invention relatesparticularly to an improvement in the type of plating machine shown anddescribed in my copending application Serial No. 596,712, filed July 9,1956. In said application, there is showna plating apparatus whichincludes a plurality of successively positioned plating tanks and acarriage mounted to reciprocate along one side of the tanks. Thecarriage has pusher elements mounted thereon for engaging and movingrail supported work carriers along the individual tanks andwithflelevators adapted for lifting the work carriers adjacent the endof one tank and depositing them on the rail above the next adjacenttank. In a single-station tank, the time of complete immersion of thework pieces in the tank amounts to the time that it takes for thecarriage to travel through its retraction stroke. In some platingoperations, the nature of the treating solution is such that the time ofimmersion of the work pieces in the solution in a single-station tank ispreferably less than the time required for the carriage to travel itsreturn stroke and means must be provided for controlling the immersiontime to a period less than the time required for the carriage to travelthrough its retraction stroke. Likewise, in a multiple station tank, itis sometimes desirable to have an immersion time which isless than themaximum time that'the work is permitted to remain in the tank by reasonof the cycling of the carriage.

It is an object of the present invention to provide a means whereby thetime of immersion of the work pieces inatank can be controlledindependently of the stroke of the carriage.

A further object of the invention resides in the provision of meanscooperating with 'the carriage and arranged to delay. the immersion ofthe work pieces in a plating tank so. that the period of immersion canbe accurately controlled within an adjustable range.

Another object of. the invention resides in the provision of a mechanismfor delaying the set-down of work carriers which is constructed suchthat its operation does not have to be synchronized with the operationof the carriage and elevators.

In the drawings:

Fig. 1 is a fragmentary perspective view, generally schematic, of aplating apparatus embodying the present invention. i i

Fig. 2 is a transverse sectional view of the apparatus with parts brokenaway.

Fig. 3 is a fragmentary side elevational view of the apparatus.

Fig. 4 is a sectional view taken along the lines 44 iBFiEJZ' i ice Fig.5 is a sectional view taken along the lines 5-5 in Fig. 2.

Fig. 6 is a fragmentary side elevation partly in section of thestructure shown in Fig. 5.

Fig. 7 is a fragmentary perspective view of a portion of the apparatus.

Fig. 8 is a fragmentary side elevational view partly in section ofanother portion of the apparatus.

Fig. 9 is a diagrammatic showing of the hydraulic circuit of theapparatus.

Referring to Figs. 1 and 2, there is illustrated a series of platingtanks, two of which are designated 10 and 12, respectively. The tanks 10and 12 are supported on a base 14. There is also supported on base 14 asby rollers 16 a carriage 18. A upright panel 20 is mounted on base 14between the row of tanks and carriage 18. At pro-selected stations oncarriage 18, there are arranged elevators 22. The arrangement thus fardescribed is substantially the same as that disclosed in my copendingapplication Serial No. 596,712; and, as disclosed in said application,means are provided for reciprocating carriage 18 longitudinally of therow of plating tanks and means are also provided for raising andlowering elevators 22 in timed relation to the stroke of carriage 18.

In the arrangement shown herein, each elevator 22 ineludes an uprightcolumn 24 fashioned with a gear rack 26 that is engaged by a gear 28 ona horizontally extending shaft 30. The drive means for shaft 30 are notillustrated. Each column 24 is provided at its upper end with an arm 32extending laterally over the plating tanks. The arms 32 of a pair ofadjacent elevators are interconnected by a frame 34 supported on boomportions 36 at the free ends of arms 32. Frame 34 includes an upperlongitudinal member 38 anda pair of lower longitudinally extendingmembers 40 which are held together by cross pieces 42 and verticalstruts 44. Lift angles 46 in the form of structural angle members aresecured to the inner sides of the lower longitudinally extending members40.

Referring now particularly to Fig. 2, the workpieces W are supportedfrom work carriers 48 which are fashioned with a pair of outwardlyextending flanges 50 ar ranged to be engaged by the lift angles 46 forelevating the Work pieces when the elevators 22 are raised. A pair ofspaced apart work rails 52 are insulatively mounted of the tanks as bybrackets 54, and carriers 48 are fashioned with shoes 56 which slidablysupport the carriers 48 on the upper edges of rails .52 when thecarriers are in the lowered position. The plating anodes 58 aresupported on bus bars 60, the plating circuit of the bus bars 60 andrails 52 being completed through the work pieces W and the platingsolution in the tank. In the case of a tank Where a plating operation isnot performed, no anodes would be placed in the tank.

With the arrangement thus far described, the operationof transferringthe work pieces W from the tank 10 to the tank 12 is the same as theoperation disclosed in my said copending application Serial No. 596,712.A work piece W supported on a carrier 48 in tank 10 as indicated bybroken lines 49 in Fig. 1 is elevated when elevators 22 are raised andthen moved horizontally to the right as viewed in Figs. 1 and 3 ascarriage 18 advances through its forward stroke to a position over tank12. Thereafter, when the elevators are lowered, the work pieces aredeposited in tank 12 at the position indicated by broken lines 51 inFig. 1. The carriage 18 then moves through its retraction stroke, thatis, to the left as viewed in Figs.

1 and 3, back to the position shown in Fig. 1. Then, on

the next cycle of the machine, the carrier 48 at the position indicatedat 51 over tank 12 will be picked up by lift angles 46 and deposited inthe next successive tank.

As pointed out previously, it is often desirable to maintain the Workpieces immersed in a tank for a period of time less than the period oftime elapsing during the retraction stroke of' the carriage. The presentinvention is directed specifically to a provision of means for delayingthe set-down of the work in tank 12 so that this time of immersion intank'1'2 can be varied from the full dwell time to a-periodapproaching-zero immersion of actually zero; that is, skipping a stationaltogether. The means for providing this delayed set-down comprises themechanism designated generally by numeral 62'. This mechanism includes apair of upright channels '64 secured to the outer side of the wall oftank 12 as by brackets 65 and provided-with vertical guide bars 66. Attheir upper ends, channels 64 are interconnected by a brace 67'; andintermediate their upper andlower ends, channels 64 are interconnectedby a yoke 68. A' hydraulic cylinder 70 is. supported on yoke 68 astrunriions 72. The rod 74- connected to the piston withinzcylinder70vprojjects downwardly through the lower end of cylinder 70. The lowerfree end ofrod '74- projects fi'eel'y through a bushing, 76 and isadjustably retained thereon by a nut-78'threaded on the lower end ofrod. 74. Bushing 76 is supported on a lower shoe 80' having. pairs ofrollers 82 at opposite sides thereof which engage guide bars 66. Shoe 80is rigidly secured to the lower end of a column. 84. To the upper end ofcolumn 84, there is secured an arm 86 which extends laterally over tank12. A second shoe 88 provided with similar guide rollers 82 is mountedat the upper end of column 84 so that the column 84 together with itslaterally extending arm 86 is guided by the four sets of rollers 82 formovement vertically along guide bars 66.

Arm 86 is provided with a depending leg 90 on which aremount'edliftangles 92'. Lift angles 92 are disposed centrally between lift angles 46on elevators 22 and the carriers 48' are fashioned with inwardlyprojecting flanges 94Which are arranged to be engaged by the inside liftangles 92. At its outer free end, arm 86 has bolted thereon a plate 96on which a roller 98 is journalled. Plate 96 is adjustable vertically onarm 86 as by bolts 97 in slots 99'. Roller 98 is aligned vertically witha guide bar ,100 mounted on the inside lift angle 46 on elevators 22.

I The uppermost position of column 84 is limited by verticallyadjustable stops 102 which engage upper shoe 88', and the lowermostposition of column 84 is limited by vertically adjustable stops 104which engage the lower end of column 84. At the same time, verticaladjustment is provided between the lower end of piston rod 74 and shoe80. To provide this latter adjustment, bushing 78 is externally threadedas at 106 for engagement with a nut 108 fixedly mounted on shoe 80 (Fig.6). 110 is provided for locking bushing 78 in. its adjusted position.

Referring now to Fig. 9, it will be observed that the upperandlower endsof cylinder 70 have conduits 112 and 114, respectively, leading thereto.These conduits are connected with a four-way valve 116 that is operatedby a pair of solenoids 118 and 119. Solenoid 1'18 is energized through atimer 120 and solenoid 119 is energized through a circuit which includesa limit switch 121. Solenoid 119 when energized shifts the spool ofvalve 122 so that oil under pressure is admitted to the lower end ofcylinder 70 to thereby raise piston rod 74. Limit switch 121 is locatedso as to be actuated and close the circuit through solenoid 119 shortlyafter elevator 22 starts moving in an upward direction. Timer 120 isarranged to receive a signal by means of suitable limit switches orthelike when the elevator 22 starts lowering from the elevated position.Timer 120 .is arranged tobe manually adjusted to vary the period ofdelay for energizing solenoid 118 and thereby delay the operation ofvalve 116 and the admission of oil under pressure to the upper end ofcylinder 70. Valve 116 connects by means of conduits 122 and 124 in acircuit which includes a pump 126 and a reservoir 128. Flow controlvalves 130 and 132 are arranged in conduits 112 and 114 to control thevelocity I A lock nut of flow of the oil from the opposite ends of thecylinder 70.

When the elevators 22 and the column 84 are in the lowered position, thecarrier 48 rests upon the rails 52 as is illustrated in Fig. 2. In thisposition, the outside lift angles 46 on elevators 22 have a clearance awith flanges 50' of carrier 48 and the stops 104 are adjusted so thatthe inside lift angles 92 have a clearance b with the flanges 94 ofcarriers 48. The adjustment of stops 104 at the lower end of column 84is preferably such that the clearance b is substantially equal to theclearance c between roller 98 and the guide rail on the inner lift angle46 on elevators 22. This adjustment is .made with the carriage 18 at theforward end of its stroke and with the elevators 22 and the column 84 intheir lowermost positions.

In operation, assuming that a carrier 48 is located on rails 52 abovetank 10 in the position indicated by broken lines 49 in Fig. 1 and thecycle of the machine is initiated, elevators 22 raise frame 34 to thebroken line position indicated in Fig. 3. However, as soon as the liftangles 46 have moved upwardly through the clearance distance a, theflanges 50 of the carrier 48 are engaged by lift angles 46 and thecarrier is elevated. If the clearance a is substantially equal to theclearance c, then when lift angles 46 engage the flanges 50, guide bar100 at its for ward end engages roller 98 so that the arm 86 and itscolumn 84 are also lifted by the elevators 22-. Rather than trying toobtain accurate synchronization of the retraction of piston rod 74 withthe raising of elevators 22, the admission of oil under pressure to thelower end of cylinder 70 is delayed slightly by means of limit switch121 so that the bushing 76 merely slides upwardly on piston rod 74 whenthe lift angles 46 are elevated. Or,

if preferred, solenoid 119 could be energized at the same instant thatthe lift angles 46 are elevated and flow control valve 130 adjusted sothat the movement of rod 74 upwardly will be at a slower rate than theupward movement of lift angles 46.

When the elevators 22 reach the upper end of their stroke, carriage 18starts moving forwardly with roller 98 still engaging rail 100 androlling thereon. At this time, piston rod 74 may have partiallyretracted so that the lower end may be raised to about the positionshown in broken lines for the nut 78 in Fig. 2. Carrier 48 is thus movedhorizontally to a position over tank 12 where the inside lift angles 92underlie the flanges 94 of carrier 98. In this connection, it will beobserved that if the clearances a, b and c are substantially all thesame, the clearance b will be maintained in the elevated position oflift angles 46; and'alignment of'the lift angles 92 in the properhorizontal plane relative to the plane of flanges 94 of the carrier isthus insured.

As mentioned above, the operation of hydraulic cylinder 70 is such thatthe upwardtravel of piston rod 74 lags the upward movement of elevators22. However, the

timing is such that by the time 'the'carriage 18 reaches the forward endof its stroke, piston rod 74 is fully retracted and the nuts 78- engagethe bushing 76. The upper stops 102 are adjusted such that the uppershoe 88 on column 84 engages these stops when the elevator columns 24are at the upper end of their stroke. Bushing 76 is adjusted withreference to lower shoe 80 so that the lower end of piston rod 74engages bushing 76 when the piston within cylinder 70 approaches theendof its upward stroke. Thus, the built-in cushioning effect incylinder 70 inctained; and at the same time, the roller 98 isnotliftedotf guide rail 108 when the piston rod is fully retracted- Afterthe carriage reaches the forward end of its stroke,

elevators 22 are arranged to automatically lower lift angles 46 and thusdeposit carrier 48 on the lift angles 92. Thus, the carrier 48 and thework pieces W supported thereby are retained in an elevated position,even though the elevators are lowered. When the lift angles 46starttolower, a signalis received by'timer 120. Then, after the timedelay for which timer is set has elapsed,

solenoid 118 is automatically actuated to admit oilto the upper end ofcylinder 70 and permit discharge of oil from the lower end of cylinder70 at a rate controlled by the setting of valve 132. When this occurs,column 84 with its arm 86 is permitted to gravitate downwardly and thuslower the work pieces into tank 12 to a position wherein the carrier 48is again supported on rails 52 and out of engagement with lift angles 46and 92; that is, to the position indicated in Fig. 2. Carriage 18 thenretracts to the position shown in Fig. l; and on the next cycle, liftangles 46 will engage flanges 50 of carrier 48 at the position indicatedat 51in Fig; 1 and transfer the carrier 48 to the next successive tank.n Thus, it will be seen that I have provided a relatively simplemechanism for delaying the set-down of the work carrier in a platingtank so as to vary as desired the time of immersion of the Work piecesin a particular tank. Furthermore, it will be observed that by the.connection between the column 84 and the piston rod 74 which enables thecolumn to move upwardly independently of the piston rod, I haveeliminated the problem of synchronizing the movement of the elevatorswith the actuation of piston rod 74 which would exist if the piston rod74 were rigidly connected to the column 84.

I claim:

1. In a conveying mechanism of the type including a rail, a work carriersupported on said rail and a transfer mechanism for lifting the carrierat a first station along the rail, moving the carrier longitudinally ofthe rail in an elevated position and then lowering the carrier onto saidrail at a second station along the rail, means for controlling thelowering of said carrier at said second station independently of saidtransfer mechanism comprising a vertically movable upright support atsaid second station, said transfer mechanism including a verticallymovable element, a one-way driving connection between said verticallymovable element and saidupright support arranged to elevate said uprightsupport when said vertically movable element is raised, means forraising and lowering said upright support, a one-way driving connectionbetween said raising and lowering means and said upright supportoperative to elevate said upright support when said raising and loweringmeans are actuated, means on said upright support positioned to receivea work carrier from said transfer mechanism when the transfer mechanismis lowered at said second station and means for operating said raisingand lowering means in a predetermined timed relation to the operation ofsaid transfer mechanism, said raising and lowering means comprising ahydraulic piston cylinder assembly having a vertically disposedretractable piston rod, said second mentioned one-way driving connectioncomprising means interconnecting said piston rod and said uprightsupport such that the upright support is elevated by the piston rod whenthe piston rod is actuated in one direction and the upright support isfree to move upwardly independently of the piston rod in response toupward movement of said verticallymovable element.

2. The combination set forth in claim 1 wherein said piston rod projectsvertically downwardly from the lower end of said cylinder, said uprightsupport having a bracket thereon through a portion of which the pistonrod projects, said piston rod having an abutment thereon below saidbracket and arranged to engage said portion of the bracket to lift saidupright support when the piston rod is retracted.

3. The combination set forth in claim 2 including vertically adjustablestops for limiting the uppermost and lowermost positions of said uprightsupport.

4. The combination set forth in claim 3 wherein said portion of thebracket comprises a bushing through which the piston rod projects, saidbushing being vertically adjustable relative to said upright support tovary the effective stroke of the piston rod.

5. In a conveying mechanism, the combination comprising a horizontallyextending rail adapted to support a work canwier, a work carrier on saidrail, a transfer mechanism for lifting the Work carrier from the rail ata first station, movingthe carrier in an elevated position along therail and then lowering the work carrier onto the rail at said secondstation, said transfer mechanism including a pair of lift membersadapted to engage said workoarrier, said lift members extendinglongitudinally of the rail and spaced transversely thereof, means forraising and lowering said lift members and for reciprocating said liftmembers longitudinally of the rail and means for lowering the workcarrier 'at said second sta-. tion independently of said transfermechanism comprising a vertically movable upright support at said secondstation, meansoperative to interconnect at least one of said liftmembers and said upright support such that the upright support iselevated in response to vertical movement of said lift members, araising and lowering means for said uprightsupport, a one-way drivingconnectionbetween said raising and lowering means and said uprightsupport operative to elevate the upright support when the raisingand lowering,means are actuated, a pair of 'lift members on said uprightsupport positioned to receive a work carrier from the lift members onsaid transfer mechanism when the transfer mechanism is lowered at saidsecond station and means for operating said raising and lowering meansin a predetermined timed relation to the operation of said transfermechanism, said work carrier being provided with a pair of flanges atopposite ends thereof adapted to be engaged by said lift members on thetransfer mechanism and wherein said work carrier is provided with asecond pair of flanges intermediate its ends and engageable with thelift members on said upright support.

6. The combination set forth in claim 5 wherein said means operative tointerconnect said upright support with at least one of said lift memberscomprises an abutment on said upright support, an abutment on one ofsaid lift members disposed vertically below said upright support andmeans for adjusting the lowermost position of said upright support suchthat when said work carrier is supported on said rail, said abutmentsare spaced vertically apart.

7. The combination set forth in claim 6 wherein said abutment on saidupright support is disposed relative to the lift members on said uprightsupport such that in the lowermost position of said upright support,said last mentioned lift members are in a plane spaced below the secondmentioned flanges on the work carrier on said rail.

8. The combination set forth in claim 7 wherein said rail is disposedsuch that when said lift members on said transfer mechanism are disposedin their lowermost position, said first mentioned flanges on said workcarriers are in a plane spaced above said lift members on said transfermechanism.

9. The combination set forth in claim 8 including means for limiting theuppermost position of said upright support for maintaining saidabutments in interengagement when said upright support is raised to itsuppermost position.

10. In a plating machine of the type having a carriage movablelongitudinally along successively arranged plating tanks to move railsupported work carriers through a succession of stations in the tanks inresponse to longitudinal movement of the carriage and having avertically movable elevator structure thereon and movable therewith,said elevator structure having lift members thereon for bodily liftingthe carriers oif the rails adjacent the end of one tank and carryingthem horizontally in an elevated position to a station above a secondtank, means for controlling the lowering of the carriers into the secondtank comprising an upright support positioned alongside the second tank,a work carrier support movable vertically on said upright support andextending laterally over the tank and overlyinga portion of saidelevator structure so that when the elevator structure is raised from alowered position, the carrier support is engaged by the elevatorstructure and moved upwardly onsaid upright support to an elevatedposition; means interposed between said carrier support and said portionof the elevator structure for permitting the lift members to-move freelyin a horizontal plane relative to said carrier support in response tolongitudinal movement of the carriage, a raising and lowering means onsaid support including a vertically movable element, said carriersupport being mounted on said upright support for movementverticallyrelative'to said element, said element having an abutment thereonengageable with the carrier support when the element is moved upwardlyto raise the carrier support and supportit inv said elevated positionand means for operating said raising andloweriug means in timed relation to the reciprocation ofthe carriage and the vertical. movement ofthe elevator structure so that the lowering of the carrier support fromsaid elevated position may be delayed relative to the lowering of theelevator structure.

11'. The combination called for in claim 10 wherein said portion of saidelevator structure comprises a pair of lift membersen'gageable with" thecarriers to raise-and support the: same in: an elevated positioninresponse to vertical upward: movement of the elevator structure.

12. The combination" called for in' claim 10 wherein the raising. andlowering means'co'mprises a piston cylinder assembly and said elementcomprises a downwardlyextendingpist'on. rod connected with said pistoncylinder assembly, said abutment being mounted adjacent the lower end ofsaid piston rod, said carrier support having an opening therethroughthrough which the piston rod extends and by means of which the carriersupport is' slidably mounted on the rod, said abutment being disposed soas to engage with the underside ofsaid. carrier support to lift thecarrier'support when the piston rod is retracted.

References Cited in the file'of" this patent UNITED STATES PATENTS2,245,673 Huenerfauth June 17, 1941 2,518,034 Ludwig Aug. 8', 1-9502,591,681 Davis- Apr. 8, 1952

